Self-luminous writing and reading device



P. M. WILLIS.

MQW

l RNEY Patented Apr. 5, 1921.'

UNITED stares smear serres PAUL M. WILLIS, OF ORANGE, NEW JERSEY, ASSIGNOR TO RADIUM LUMINOUS MATERIAL CORPORATION, OF NEW YORK, N. Y.,-A CORPORATION 0F DELA- *i WARE.

SELF-LUMINOUS WRITING A*AN D READING DEVICE.

Patented Apr. 5, i921.

Apflication mea November 17, 1917; serial No. 202,608.

To all whom t may concern.'

Be it known that I, PAUL M. WILLIS, a citizen of the United States, residing at Orange, in the county of EssexV and State of New Jersey, have invented a certain new and useful Self- Luminous Writing and Reading Device, set forth in the following specification and illustrated in the accompanying drawings.

This invention is a self-luminous device for military or general use. Its object is to provide a simple and compact instrument which can be employed in the dark for making or reading notations and computations without recourse to any light extraneous to the'device itself, and to provide a self-luminous device which can be conveniently employed in many circumstances for night signaling over short distances or for marking the location of objects or persons and for various other purposes which may beserved by a self-luminous article. Y

The invention is exemplified in the accompanying drawings in which- Figure 1 is a plan view of one form of the invention;

Fig. 2 is a transverse sectional view of the device of Fig. 1, taken on the section line 2, 2 of Fig. 1.

Fig. 3 is a sectional view of the self-luminous pivoted plateof Figs. 1 and 2, taken on the section line 3, 3 of Fig. 1; and

Fig. 4 is a similar sectional view of a modified form ofthe self-luminous pivotedplate. v

In the device of Figs. 1, 2 and 3, an oblong beveled glass plate 5 is providedV with parallel grooves 6 in one surface. These grooves arev filled with radio-active selfluminous material. A backing sheet 7 is held against the grooved surface of the glass plate, being in this instance a compressible white or light-reflecting paper sheet compressed between the glass plate and a metal backing plate 8 having its margin 9 crimped or bent over the beveled edge of the glass. Also the backing sheet 7 may be suitably cemented to the flat surfaces of the glass plate between its grooves.

This scheme will retain the radio-active self-luminous material in powder form without the admixture of an adhesive agent into the powder, which generally impairs its self# luminous efficiency." The masses of selfl their easy erasure.

1mnin0us`meterai-raained in the holding.

grooves will generally be' in themselves transparent or translucent and the lightreflectingsheet 7 will economize their lightf by reflecting it back'th'rough the self-luminous material and `through the kglass plate 5 to its outer surface.

The outer surface of the glass plate 5 mayY be ground or otherwise madev suitable for y receiving chirographic or other characters.

A lug 10 may be secured to the margin of the metal backing plate 8and may be. perforated as at 11. By this lug'the self-luminous plate may be conveniently secured to a person or obj ect, for instance it may be hung on the back of an o-flicer leading men through the trenches or kon patrol. Also the device thus constituted may vbe used as a signal light over short distances.

By means of the perforated lug 10and a suitable bolt 12 the self-luminous plate may be detachably pivoted to the central perforation in the disk 13 of celluloid or other lighttransmitting material, so that the self-lumithe disk may be suitably translucent and adapted to receive on its upper surface the marks of a pen or pencil and to permit of p The entire device thus assembled may be used as a signal ror marker as mentionedV of the self-luminous plate separately. y

In the modification of the self-luminous plate shown in Fig. 4, the self-luminous portions by light transmittedv through it, and

powder 15 is compressed between a smooth glass plate 14 and a compressible light-reiiecting back sheet 16 retained by the mteal backing plate 17.

The invention may be practised in other ways within Ythe scope 0f the following'V Y claims.

1. A device comprising a transparent plate 'withrr-ecesses 1n one surface, a reiiect- .ing backing cemented to said recessed surface of the transparent plate, and self-luminous powder in said recesses.

2. A device comprising a transparent plate with recesses in one surface, a backingplate' secured thereto adjacent its recessed surface, a eompressible backing compressed between said backing-plate and said recessed surface of the transparent plate, and selfluminous material in said recesses.

3. A device comprisingrv a transparent plate with grooves in one surface, a backingplate secured thereto adjacent its grooved surface, a reliecting Y compressible y.backing compressed between said backing plate and the grooved surface of the transparent'plate, and selfluminous powder compressed in said grooves.

t.v A device comprising a light-transmit-k ting plate, and a self-luminous plate'of lesser area pivoted on one side thereof in position to swing into register with succes-l sive portions ofthe light-transmitting plate.

5. A f device comprising a .translucent plate with awriting surface adapted for re- Y ceivingmarks from a writing instrument,

and a self-'luminous member pivotedtosaid plate adjacent to itssurface opposite its'said writing surface. v e

6. A device comprising a light-transmit ting writing platen, and a self-luminous member movably connected under Y said platen by means permitting said member to move under andilluinine successive portions thereof.

In testimony whereof, Ihave aiiixed myk signature to this specilication VPAUL M. wiLitis."I 

